Dimitri is right, the best way to do this is via the original application.
If you have to do this in the PDF file, you can certainly use a button as already explained, but my preferred way of doing this would be via the annotation tools in Acrobat: Bring up the Comment pane on the right side of Acrobat's user interface, then go to the "Drawing Markup" tools and select e.g. the rectangle tool. After you place your rectangle on your document, you can right-click on the rectangle border and select Properties from the menu. Here you can now select the border color, the line width and the fill color. If you want to place this rectangle around an image and the image should still be visible, you need to set the fill color to transparent.
Karl Heinz Kremer
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